The impression of an image persists on the retina for about _________ of a second.

• 1/10 th

• 1/8 th

• 1/16 th

• 1/5 th

The reflection formed by the plane mirror is ...........

• vertical inversion

• a real image

• lateral inversion

• an enlarged image

The frictional force exerted by fluids is also called..........

• drag

• buoyancy

• upthrust

• convection

The distance-time graph for the motion of an object moving with a constant speed is a .............

• Dot

• Circle

• Straight Line

• Curve

Who discovered electricity and invented the lightning rod and bifocals?

• Kirkpatrick Macmillan

• Benjamin Franklin

• William Henry Fox Talbot

• Sir Alexander Fleming

If the force applied on the object is in the direction of its motion, the speed of the object.......

• increases

• stops

• decreases

• no effect

If an object moves in a circular path with uniform..........its motion is called uniform circular motion.

• speed

• time

• velocity

• acceleration

Friction is caused by the ......... on the two surfaces in contact.

• irregularities

• smoothness

• densities

• gaps

An image formed by a concave mirror on a screen is called........

• Virtual image

• Real image

• Inverted image

• Erect image

Convex and concave mirrors are examples of

• plane mirrors

• spherical mirrors

• inverted mirror

• erect mirror